Combined shut-in and back circulation tool



Dec. 8, 1953 M. o. JOHNSTON 2,661,802

COMBINED SHUT-IN AND BACK CIRCULATION TOOL Filed March 9, 1950 2vSheets-Sheet 2 1N V EN TOR.

Bye/9a@ am Patented Dec. 8, `1953 4v2,661,802 'oormINEDjsHUT-'I'N AND"BACK CIRCULATION `TOL Mordica 0. Johnston, Glendale, "Calii, assigner,

wb'y mesne assignments, 'to Johnston Testers, Inc., Houston, Tex., acorporation of Delaware ApplicationMarch 9, 195D,"Serial"o. ilfl' 4Claims. 1

This invention relates to an oil well tool and particularly pertains toa combined :shut-"in Fand back circulation tool.

In oil well drilling operations -it is common practice to pack off thewell bore at a `"desired level and obtain an entrapped sample of 'ftheformation iiuid yield by the use of fa Iformation tester. In thisoperation it is 'desirableto make a test to ascertain the fluid pressureexerted vby the connate fluid in vthe formation and it is Aalsodesirable to produce 'a back circulation of the drilling uid withinwhich the testing tool is 'submerged. A tool vfor these purposes shouldbe 'associated with the tester and disposed 'between the retaining valvestructure of the tester and the trip valve which occurs atthel'ower-end-of a supporting string of pipe. It is the principal object ofthe present invention therefore ito provide a valve structure which maybe manipulated from the surface of fthe well through the supportingstring o1" pipe and by which the connate fluid passing through the`tester 4may be shut 1in to obtain a desired iiuid pressure reading.after the test is 'made or whichstructure Vmayb'e inanipulated toperform `a back vscuttling Vactionin the well for emergency purposes andto allow fthe drilling fluid to enter the tool above 'the comfiate iiuidtherein.

The present invention contemplates the provision of a tubular housinginterposed between the retaining valve and trip valve 'of a formationtester and which tubular housing may be manipulated to permit connatefluid to owt-hrough Athe tester and above the retaining valve where itis restrained and to thereafter now upwardly into the drill pipe whenthe trip valve is opened,`

said structure embodying the use of a back scuttling valve carriedwithin the tubular housing and capable of manipulation to establishcommunication between the interior of the shut-in valve structure andthe well bore whereby drilling fluid may enter the valve structure whendesired.

The invention is illustrated by 'way rof 'example in the accompanyingdrawings in which:

Figure 1 is a View in elevation showing 'the application of the presentVinvention to the usual formation tester assembly.

Fig. 2 is an enlarged fragmentary View in 'longitudinal section vas seenon the line 2-"2 of Fig. 1

and 'shows the construction of the Vupper 'section vorally indicated inFig. 1 at i5.

has a threaded connection with the housing of a trip yvalve'structurell. The trip valve structure is formed at its lower end with a 'pin v"i2which extends into a boX I3 of a sub lf'l which forms a 'part of the'combined shut-in valve and lback V'scuttling kvalve with which theVpresent invention 'is particularly concerned and which valve is `gen-The sub It has a-central passageway l5 through itA which terminates inVa threaded counterbore il. The lower end of 'the sub is reduced indiameter as indicated a-t |98 and is externally threaded at i9 to'receive "an adjusting cap 2t. Threaded into the bore -Il andextendingdownwardly-from the vsub is the upper tubular mandrel section 2i. Nearthe upper end of the mandrel section 2i and -below its threaded 4portionis "a shoulder 22 against which the lower end 'of the adjusting cap 26abuts. The lower end `oi the mandrel 2| is Vformed with an internally'threaded counterbore '23 to receive the upper threaded end of theVVmain vsection 24 of the tubular mandrel. The upper section 2l of thetubular mandrel has a central bore 2'5 and the lower "section has acentral`bore r2li longitudinally aligned therewith and extendingentirely therethrough. Mounted Vupon "the main section 2'4 is a ballthrust bearing 2l, the upper race 28 Aof which provides a seat for acollar `compression lspring 2'9, the 'upper end of 'the vcompressionspring 29 resting against the lower face 'or the adjustable cap 2G. Thethrust bearing has` a lower 'race 30 which `rests against the upperf'ace of a .split collar V'31. The parts 'of this collar .are heldtogether by clamping bolts 32. The collar rests against the end face ofthe upper section 3'3 'of a. tubular housing which is formed at itslower end `with 'a threaded pin 3Q to extend within a "threaded `lbox 35of an intermediate housing section V36 carrying a sliding nut 3l. lThenut 31 is cylindrical and lits Within ka central 'bore 38 oi "thevvintermedia'te housing section 36. This nut is formed with aninternally threaded bore 39 comprising acme or other type coarse threadsand receives threads fall formed upon a length of the main tubularmandrel section 24. The main tubular mandrel section is formed with acollar il which in its upper position abuts against the lower end faceof the pin 34 of the upper tubular section 33. Directly above the collarand extending radially from the mandrel are lugs 42 which in theiruppermost position register with keyways 43 cut into the inner wall ofthe upper housing section 33. The

upper end of the housing section 33 is formed.l

with a counterbore 44 to receive packing 45 which circumscribes themandrel 24 and is held in position by a stuing gland 4G threaded intothe upper end of the counterbore d4 and through Y which the mandrel 24extends with a substantially tight iit. The threaded section 39 of thenut is relieved at its lower end so that a clearance opening il willoccur within the nut and below the lower end of the threaded section 39.Communicating with the cylindrical bore 41 within the nut 37 is athreaded bore i8 which receives a perforated mandrel section 49. Thisvalve section has a central longitudinally extending passageway 59through which fluid may ow. The walls of the tubular valve section ofthe perforated mandrel section 49 are formed with radial ports l for apurpose to be hereinafter described. The lower end of the mandrelsection 49 is fitted with a check valve structure 53 comprising a frame54 which supports a spring 55. The spring 55 presses yieldably against avalve ball 59. rEhe valve ball 56 is held against a valve seat 5l whichis mounted directly at the lower end of the perforated mandrel section49 so that the valve 56 will act to obstruct the flow of fluid into thepassageway 59 of the mandrel section 49. The perforated mandrel section49 extends downwardly beyond the end of the intermediate housing sectionBt. The lower end of the housing section is fitted with a tubularextension 59 of reduced diameter. VA counterbore 59 is formed in thetubular extension 58 to receive packing 69. A nut 6l is threaded intothe outer end of the counteroore 59 to hold the packing. The extension58 is externally threaded at 62 to engage threads 93 formed at the endof a coupling sub 64,. The mandrel 49 extends downwardly through thecoupling sub 6d and therebeyond. A counterbore B5 is formed within thissub to receive a packing 6B. This packing is of relatively long lengthand serves not only to pack the mandrel so that it may have longitudinalmovement and still remain fluid-tight but also to pack off the ports 5|when the mandrel section 49 is drawn upwardly to a position where theports 5l will be closed. At the upper end of the extension sub 64 is anenlarged bore 6'! which provides a fluid passageway to establishcommunication between back circulation ports 68 and the ports 5l of themandrel under certain circumstances. The back circulation ports 68 areformed through the Wall of the sub S4 and permit well fluid underhydrostatic pressure to flow into the tool as hereinafter described. Thelower end of the connecting sub 64 is formed with a threaded extension69 which is threaded into the upper end of a lower housing section 1B.The lower housing section 'I0 4terminates with a pin section 'H whichmay be threaded into the box portion of the upper end of a desirednumber of stands of pipe above the usual retaining valve structure.`rIhe lower housing section l0 is formed'with a relathreaded to receive atemporary plug i8.

tively large bore 'I2 which terminates in a smaller longitudinallyaligned fluid passageway 'i3 extending through the pin section 'i l.

In the operation of the present tool, fluid under pressure may beentrapped between the bore 'i2 of the lower housing section 'i9 and theretaining valve under certain conditions and it will be necessary torelieve this pressure when the tool is withdrawn from the well in orderto disassemble the structure. In order to accomplish this a releasingcheck valve is provided as generally indicated at ibi. This check valvecomprises a housing portion i5 threaded into a bore 'E5 extendingradially from the fluid passageway 23 and through the wall of the pinsection 1l. The housing 'l5 is formed with a central bore The outer endof this bore is The inner end of the bore terminates in a valve seat 'i9(Fig. 6) to receive a valve ball 89. The ball 9i! is yieldingly held onthe seat by a spring 5l which is positioned by a retaining cap 92. Theretaining cap 92 is threaded onto the inner end of the housing 'I5 andhas a central fluid opening 83.

In order to bleed the entrapped fluid from the bore l2 in the lowerhousing section 'lll a tool B4 is provided as generally indicated inFig. B of the drawings. This comprises a housing 55 formed with athreaded stem 86 at one end and a threaded counterbore 8l at itsopposite end. The threaded stem 36 is designed to be screwed into theopening in the valve housing l normally receiving the temporary plug i8.A bore S3 extends through the housing from the counterbore Si andthrough the stem 89. At a point intermediate the ends of this bore alateral threaded passageway 89 is provided to receive a threadedcoupling 99. This coupling is carried by a bleed tube 9i. The threadedcounterbore 8l of the housing 85 carries a tubular packing sleeve 92.This extends in longitudinal alignment with the bore 8S and receives anoperating pin 93. rlhe cuter end of the pin 93 is threaded at 94 andfits into a threaded bore of the sleeve 92. The opposite end of the pin93 has an extension portion 95 which passes into and through the bore 83of the housing 85. The pin is made fluid tight by a packing 95. Thispacking is held in position by a packing nut 91.

In operation of the present invention the combined shut-:ln and backcirculation tool is constructed as shown the drawings and is assembledwith other instrumentalities as particularly shown in Fig. l of thedrawings. As previously stated this is preferably used in connectionwith the formation or casing testing structures of the Patent No.2,073,197 issued to Mordica O. Johnston on March 9, 1937, entitled WellTesting Method and Apparatus Therefor. In this structure a packer 99 iscarried at the lower end o a tester 99 which includes a retaining valve99. At the lower end of the packer there is a perforated anchor it!through which connate uid may iiow upwardly through the packer and thetester structure 99. 'When the packer 98 is set and the weight oi thedrill string i9 is imposed upon the retaining valve ISB `of 'which ittravels upwardly through the center acci-sos then through the centralpassageways 25' and?" 26 to the sub ld. In Viewv of' the tact that thetrip valve li above the sub I4 is normally closed circulation throughthe tool I willi be interrupted by the trip valve Il. When the tripvalve is opened by dropping a go-devil thereon or through some otherinstrumentality a sample of the connate fluid may pass upwardly throughthe tester Q9 and the tool I5. It is preferable to interpose a pluralityof stands of pipe between the retaining valve lli and the combinedshut-in and back circulation tool l5, so that an entrapped sample may beobtained when the shut-in tool is closed as will be hereinafterexplained. lt is also to be understood that in common practice apressure recording device is disposed within the perforated anchor sothat the pressure of the connate fluid may be recorded. Normally thetool generally indicated at l5 isset as indicated in Figs. 2 and 3 ofthe drawings. At this time the ports si will be open below theconnecting sub 54. In the event that it is desirable to entrapa shut-insample weight is applied' to force the lugs gi2 downwardly out ofengagement with keyways i3 and against the action of the spring 2s; Thedrill string and the mandrel section 241 may then be rotated so that thethreaded section 40 of the mandrel will act to move the sleeve upward'-ly. The pitch of the threads 39- and lil are such as to require that themandrel shall be rotated approximately seven times in order to draw theports 5l into a closed position within the packing et. When the ports 5lhave been closed the connate fluid which has risen through the opentester and the extra stands of pipe as indicated at le? in Fig. 1 of thedrawings will be entrapped by the closing of the ports 5| and by theclosing or the retaining valve lll@ in the tester QS as the string ofpipe is lifted preparatory to being withdrawn from the well. It will beobvious that the entrapped fluid will be under the pressure of theconnate fluid, which pressure will be recorded by the pressure recordingmechanism placed within the perforated anchor. The entrapped sample offluid cannot at this time pass upwardly through the drill string oroutwardly through the valve structure '14, thus the shut-in pressure maybe obtained.

In the event that it is desired to complete the test and withdraw thestring of pipe and the testing tool from the well, pressure on thestring of pipe is relieved on the testing tool so that the combinedshut-in and back circulation tool and the tester t9 with its packer 98may be withdrawn from the well. After the tool i5 has been withdrawn therecovered sample entrapped within the section of drill pipe |32 and thebore 'l2 at the lower end of the section 'it may be removed by use ofthe tool 84. This is accomplished by first unscrewing the plug 18 in thevalve structure 'it and thereafter screwing the extension 86 of the tool8d in the threaded bore from the threaded plug 18. When the extension 86has been screwed into position the pin 95 may be advanced by itsrotation and by the action of the threads 94 on the pin. This will forcethe pin S5 inwardly to encounter the valve ball 8D which will be movedfrom its seat against the expansive action of spring 8l. When this takesplace the entrapped iiuid within the bore 'l2 and the length of pipe |02will be expelled by the pressure which has been imposed upon the fluid.The entrapped iiuid which is the retained sample will then bleed outthrough the pipe 9| into a suitable receptacle.

En casecf emergency when: the packer 3.8i is. set it may be: desirableto impose a counter uid pressure upon the connate uid. in the well. Thismay be normally accomplished by creating a back circulation of fluid.downwardly through the string of pipe and theA tester. The backcirculation ows downwardly throughy the tubular mand-rel t'ofmove thevalve ball. ofi of' its seat 57:. In the event however that it isdesiredto imposel the pressure of the hydrostatic fiuid head of the wellupon the connate fluid the supporting string lil` is rotated in the samedirection aspreviousl'y described for the rotation or" the threadedmandrel 2li' to draw the radial ports 5i of the perforated mand-rel 49upwardly through the packing tt. Further rotation of thev threadedmandrel will draw the ports 5l upwardly into the bore 51 of theconnecting sub dit. The duid within the well bore may then pass inwardlythrough the back circulation ports t8 and into the space 61. This fluidis under the pressure exerted. byY the hydrostatic head of fluid withinthe'well and this fluid will then be forced through the ports 5| anddownwardly through the pas.- sageway 5e. to the ball valve 56. Thisvalve is then opened so that the fluid under hydrostatic pressure may beimposed upon the connate fluid which. is attempting to rise from beneaththe packer S8 and through the tester t9.

It willv thus be seen that the combined. shut-in and back. circulationtooll here shown is compact in. construction, and that it may beoperated easily to insure that a shut-in pressure may be recorded, thata sample of the shut-in uid may be obtained, and that under emergencyconditions it is possible to impose a superior' pressure upon that ofthe connate fluid' either by pump pressure through the drill string orhydrostatic pressure exerted by the column of fluid standing above thetool in. the well bore.

It is to be understood that the nut. 3l. and the intermediate housingsection 35 are suitably splined together by splines 3l so that the nutmay move longitudinally oi the housing section te as. the threadedsection lil on the main tubular mandrel section. 2d is rotated.

While I have shown the preferred form of my invention as now known tome, it will, be under'- stood that various changes may be made incornbination, construction and arrangement of parts by those skilled inthe art, without departing from the spirit of the invention as claimed.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. An oil well tool for creating a shut-in pressure or back circulationwithin a string of pipe suspended in a well which comprises; an outertubular housing adapted to carry an element formed with a well packer atits lower end and adapted to be connected to a supporting string of pipeat its upper end, said tool including: a tubular housing, a threadedtubular mandrel eX- tending upwardly therethrough and connecting withthe supporting string of pipe, a traveling nut within the tubularhousing and through which the threaded tubular mandrel section extends,a perforated mandrel section secured at the lower end of said nut andextending downwardly through the lower portion of said tubular housing,a check valve at the lower end of said perforate mandrel section topermit the outow of uid from said mandrel section, packing means withinthe lower portion of the housing and through which the perforate mandrelsection extends, and ports through the side wall of the lower portion ofthe housing establishing communication between the interior thereof andthe fluid within which the tool is submerged, the mandrel section beingformed with radial ports which may be positioned by the rotation of thethreaded mandrel section as the threaded nut is moved to dispose theports in the mandrel section in an uncovered position below the packingand an uncovered position above the packing and a closed position withinthe packing and intermediate the ends thereof.

2. An oil well tool of the class described, comprising a tubularhousing, a traveling nut slidably but non-rotatably received by thehousing, a tubular mandrel telescopically received within the tubularhousing and having means at its upper end for connection to a supportingstring of pipe and having its lower end threadedly engaging said nut, atubular section carried by the nut, extending downwardly therefrom, andhaving its lower end closed to the upward ilow of fluid thereinto,packing means within the housing below the nut and through which thetubular section extends, said housing having ports in the side wallthereof disposed above the packing means, said tubular section havingports formed in the side wall thereof initially disposed above thepacking means in communication with the ports in the housing and adaptedto be placed, upon rotation of the mandrel, within the connes of thepacking means, or below the packing means in communication with theinterior of the housing.

3. An oil well tool of the class described, comprising a tubularhousing, a traveling nut slidably but non-rotatably received by thehousing, a tubular mandrel telescopically received within the tubularhousing and having means at its upper end for connection to a supportingstring of pipe and having its lower end threadedly engaging said nut, atubular section carried by the nut, extending downwardly therefrom, andhaving its lower end closed to the upward iiow of fluid thereinto,packing means within the housing below the nut and through which thetubular section extends, said housing having ports in the side wallthereof disposed above the packing means, said tubular section havingports formed in the side wall thereof initially disposed above thepacking means in communication with the ports in the housing and adaptedto be placed,

8` upon rotation of the mandrel, within the confines of the packingmeans, or below the packing means in communication with the interior ofthe housing, other packing means below the nut. disposed above thehousing ports and through which the tubular section extends.

4. An oil well tool of the class described, comprising a tubularhousing, a traveling nut slidably but non-rotatably received by thehousing, a tubular mandrel telescopically received within the tubularhousing and having means at its upper end for connection to a supportingstring of pipe and having its lower end threadedly engaging said nut, atubular section carried by the nut, extending downwardly therefrom, andhaving its lower end closed to the upward flow of fluid thereinto,packing means within the housing below the nut and through which thetubular section extends, said housing having ports in the side wallthereof disposed above the packing means, said tubular section havingports formed in the side wall thereof initially disposed above thepacking means in communication with the ports in the housing and adaptedto be placed, upon rotation of the mandrel, within the confines of thepacking means, or below the packing means in communication with theinterior of the housing, other packing means below the nut, disposedabove the housing ports and through which the tubular section extends,spring means urging the tubular mandrel upwardly relative to thehousing, and means preventing rotation of the tubular mandrel relativeto the housing, responsive to downward movement of the mandrel relativeto the housing to release the mandrel for rotary movement.

MORDICA O. JOHNSTON,

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,625,044 McKeonn Apr. 19, 1927 1,984,375 Johnston Dec. 18,1934 2,073,107 Johnston Mar. 9, 1937 2,197,078 McKinley Apr. 15, 19402,229,636 Boynton Jan. 28, 1941 2,327,610 Savitz Aug. 2d, 1943 2,337,752Johnston Dec. 28, 1943 2,404,825 Brown et al July 30, 1946

